Code Design of Space-Time Block Codes Coded Low-Density Parity-Check Code and System Performance Analysis

In multiple input and multiple output system of wireless communications, space time coding using multiple transmit antennas is the attractive technique for high bit-rate and high capacity transmission. Methods for providing transmit diversity in communication over fading channels also been concerned.Although Space-Time Block Codes has full diversity gain but not coding gain.The concatenation scheme of STBC codes and LDPC (STBC-LDPC) was proposed and it has been shown that the STBC-LDPC can achieve the good error rate performance and coding gain. Low-density parity-check (LDPC) codes ,as it is the good error correcting codes achieving the near Shannon limit performance.In this paper, a concatenation scheme of LDPC codes and STBC which should apply full transmit rate with multiple transmit antennas is proposed. Refering to it as the ABBA-LDPC and OSTBC-LDPC.We evaluate the bit error rate (BER) of the two schemes in a quasi-static Rayleigh fading channel by the computer simulation. We show that the BER of the ABBA-LDPC is better than that of the STBC with same antennas in a quasi-static Rayleigh fading channel,and also it is better than OSTBC-LDPC which uses real constellation. When receive antennas increasing ,the diversity gain will be increasing too.